This shared instrument application is to support the purchase of a small animal radiation research platform (SARRP). The technology available from Xstrahl is unique and combines a cone beam CT with a computer controlled rotating treatment x-ray tube. In combination with the treatment planning software, this hardware allows for 3-dimensional radiotherapy treatment planning and delivery to model organisms that mimics the volumetric approach used to treat human tumors. This next-generation system leverages the recent advances in small animal CT to generate true image guided radiotherapy, or IGRT. The device incorporates a 360o rotating gantry with a stage that rotates and translates in 3 dimensions to allow for multiple x-ray beamlets to be delivered from any angle and converge upon the tumor. This system will replace the current technology at Ohio State University that is based on 50 year old design for cabinet X-ray machines. The cabinet x-ray device at Ohio State University is an RS2000, a point source X-ray generator fixed to the top of a sealed cabinet. In order to treat animals, one must use manual placement of lead shielding in such a way as to shield a portion of the mouse and allow x-ray delivery only to the model tumor. The SARRP will enhance the research of 6 major users with 9 currently funded NIH projects that span the departments of Radiation Oncology, Neurosurgery, and Molecular Virology, Immunology and Medical Genetics at OSUCCC and the Experimental Therapeutics program at Nationwide Children's Research Institute. In addition, the SARRP device will be incorporated into the training for the graduate program in medical physics run in the department of Radiation Oncology. Finally, the SARRP will be combined into the services that are offered at the OSU Neuroscience Center (P30) core for orthotopic brain tumor implantation. This core is designed to support the development of new technologies for the treatment of brain tumors. Current and future investigators using this core will now be able to incorporate radiotherapy with their novel modalities in the hope of generating innovative, synergistic therapeutics to treat brain tumors.